Alarm for air-brake systems



R. L. FLINN. ALARM FOR AIR BRAKE SYSTEMS.

APPLICATION FILED EEB. 3, I92!- 1,3s7,o02. Patented Aug. 9, 1921.

/ V IN VEN TOR.

- I ATTORNEY.

UNITED STATES no AnnL. ELINN, or nnnnron, MO TA A- ALARM non AIR-BRAKE SYSTEMS.

Application filed February 3, 1921. Serial No. 442,121.

To all whom it may concern Be it known that I, ROLAND L. FLINN a citizen of the United States, residing at Al berton, in the county of Mineral and State of Montana, have invented certain new and useful Improvements in Alarms 'for Air- Brake Systems, of which the following is a specification.

This invention relates to alarms for air brake systems the primary object of which is to provide a device which will automatically sound an alarm as soon as'there is a break in the air line or lack of pressure due to failure of thepumpsto operate, or diminution ofthe power' from any cause.

Another object of the-invention'isto'provide a simplifiedmechanism which maybe conveniently connected to the air line at any desired point and is equipped with a whistle or other desired audible signal means which may be'place'd in the cab ofthe train, or otherwise positioned where it will be readily heard by a member ofthe train crew.

The above and other objects of this invention will be in part described'and in part understood from the following description of th present preferred embodiment taken in connection with-the accompanying drawings, wherein:

The figure is a vertical sectional view of the device constructed in accordance with this invention, a portion thereof being shown in side elevation. I

In the drawings, a casing 1' is-provided, which in this instance is shown to be of a cylindrical configuration, a portion of the bottom wall thereof being straight to provide an annular seat 2, the central-portion of the wall being inclined downwardly, as indicated at 3, and issues into an --externally screw threaded inlet terminal 4:. The inlet terminal is adapted for connection with the train line and is tubular to permit the passage of air therethrough and into the casing equipped with a port'9 on' the side opposite to that which carries the port 6', and is in communication with the interior'ofthe cas ing and also with an alarm mechanism 10, which in this instance consists of a whistle.-

A shaft 11 is concentrically arranged in the casing 1, and has screw threaded thereon, remotefrom its lower end, an upper pisto'n 12. A lower piston 13 is'screw threaded upon said shaft in proXimityto thelower endof the latter, The said lower piston is opposite end of the spring is in engagement with a cup 17 which is arranged on'the'shaft 11 and is engaged against one end of a gland 18. The said gland is provided with ex ternal screw threads 1 which engage corre sponding threads formed centrally in the cap 5. The bore of the-gland is smooth throughout and has the shaft ll slidabl'yv mounted therein. v

A puppet valve 19- is mountedupon the shaft 11 between the closed end ofthe piston 13 and the piston 12. Normally, the, valve lies in-snug engagement with the closed-end of the piston 13. The latter, however, is provided with one or'moref openings,- such as that indicated at 20-which permit ingress of air through the inlet terminal} andjnto the piston 13 for the purpose of elevating the puppet valve. able on theshaft 11 it is apparent that as soon as the air pressure through the terminal 4: is cut off, the puppet valve'will gravitate into engagement with the closed end of the piston. r I

In use of this device, the spring 15 will be tensionecl to a certain point through the manipulation of the gland 18. Consequently, pressure of air from the train line through the terminal 41 and into the casing must be of a predetermined pressure 1n order to elevate the pistons 12 and 13 against .theresistance of said spring 15. The air in entering the casing passes through the opening or openings 20, thereby Since the said valve is slidelevating the puppet valve 19 into engagement with the piston 12 so as to elevate the entire structure consisting of the shaft 11 and pistons 12 and 13. After having ele vated the pistons 12 and 13 to a predetermined point, the air will be permitted to pass into a bypass 21, one end of which communicates with the casing and the opposite end with the port 6. Consequently, a small volume of air will pass through the port 6 and into the reservoir 8 which latter may be of any desired size. As soon as the pressure of air through the terminal 1 is cut off, the pistons 12 and 13 will be returned to their normal positions by the expansive ac.- tion of the spring 15, thereby bringing the annular way 1 into communication with the ports 6 and 9. The air contained in the reservoir 8 will be permitted to return into the casing through the way 14 and ultimately passes .out through the way 9 for blowing the whistle 10. If the pressure of air through the terminal 4 should merely be slightly diminished, the air coming through the terminal 4 and passing through the openings 20 will be insufficient to operate the puppet valve 19 against the piston 12, consequently the air will travel beyond the periphery of the puppet valve as inclicated at A in the drawings and from thence will pass directly through the port 9 so as to cause a continuous blowing of the whistle.

In order to prevent casual displacement of the piston 13, a nut 22 is threaded on the lower end of the shaft 11 which may, of course,be readily removed to permit removal of the piston when desired. Also a vent opening 23 is formed in the wall of the casing 1, preferably between the cap 5 and piston 12. Moreover, in order to prevent casual displacement of the cap 5 a set screw 24 is arranged through the casing and engages the cap.

Various changes may be made in this de vice, especially in the details of construction, proportion and arrangement of parts without departing from the spirit and scope of the invention as covered by the appended claims.

What is claimed is:

1. An alarm for air .brake systems including a casing engageable with the air line and equipped with means movable under air of predetermined pressure to permitthe exhaust of a certain volume of the air from said casing, a container in communication with said casing to receive the air exhausted from the latter, and alarm mechanism in communication with said casing and said container to permit passage of air from said container into said mechanism for sounding the alarm when the air pressure into the casing is insuflicient to operate said means.

2. An alarm for air brake systems including a casing equipped with pistons movable in sequence by pressure of air to permit exhaust of a portion of the air through the casing, a container in communication with said casing to receive the air exhausted from the latter, and alarm means in connection with the casing and operable by the air pressure wherebyvdiminution of the air sup ply will permit return of the air from said container and intosaid alarm means for operating the latter.

3. An alarm for air brake systems including a casing engageable with the air line and equipped with pistons movable into an open position under a predetermined pressure of air to permit exhaust of a fractional portion of the air flowing into the ..casing, a container in communication with the casing to receive'the air exhausted from the latter, one of the pistons having an annular way formed therein which communicates with the container when the piston is closed, and a signal adapted to communicate with said way to permit direct passage of air from said container through the way and to the signal for operating the latter.

In testimony whereof I affix my signature in presence of two witnesses. T

ROLAND L. FLINN.

Witnesses:

M. L. MILLER, W. C. MILLER. 

